Explorando dados polarimétricos SAR para o estudo de processos meteo-oceanográficos na margem continental do Brasil
Polarimetric ALOS/PALSAR scenes were used to explore the behavior of metocean processes in the South Brazil Bight. The parameters evaluated from two different polarimetric approaches, the Cloude-Pottier decomposition and Kudryavstev et al. quad-pol analysis, were the basis for the study, supported by SST and scatterometer wind data. Although the traditional H-α diagram labeled all the pixels as ‘Bragg scattering dominant’, when the results were analyzed in detail, subtle variations enabled a preliminary discrimination of data in three regions, where the signal is probably composed by different groups of scattering mechanisms: (1) [H: 0.11-0.14; α: 4.5º-5.5º; A>0.45] region under influence of Subtropical Shelf Front (Río de la Plata plume), moderate wind from S-SW and probably a strong coastal current; (2) [H: 0.13-0.15; α: 5.0º-6.5º; A>0.45] region under influence of Subtropical Shelf Front and low wind from SE; (3) [H: 0.16-0.17; α: 5.5º-6.0º; A<0.3] region under influence of Brazil Current and low- to-moderate winds from SE. Kudryavtsev’s parameters were complementary for that initial description of scattering mechanisms in each region. The polarimetric approach proved to be promising to discriminate metocean processes and the related scattering mechanisms. More scenes and areas should be analyzed in a near future to refine the study and start the development of a classification scheme for recurrent metocean processes at the Brazilian Margin.